In search of image quality

It appears Sigma's production of the 18-35 isn't keeping up with demand. While it's available on the Sigma mount, it's on backorder for Canon and Nikon (who will be their largest customer base). Until they can catch up with that demand we probably will wait a little longer for the A-mount version. But it might just be worth the wait. This is clearly the most intriguing and exciting new APS-C lens to come out in a long time.

I've seen the Nikon mount at least come into stock once every few weeks. But it only stays in stock for a few days to a week at most, then it is backordered again for 2-3 weeks.

The Canon mount I haven't seen pop in stock as frequently at the Nikon mount. It stays on back order for what seems twice as long before coming into stock ever so briefly.

The Sigma mount always shows in stock. I guess that comes to show how few people are using Sigma cameras.